Galileo UVS Observations of Fragment G Impact

Direct observations of impact G by Galileo UVS

October 13, 1994

The Galileo Ultraviolet Spectrometer (UVS) team has detected the
Shoemaker-Levy 9 G impact in data recently played back from the
spacecraft tape recorder. The UVS instrument was scanned back and
forth across Jupiter. Each scan lasted about 5 seconds; Jupiter
traversed the UVS slit in about 2 seconds. UVS observations were
made at a fixed wavelength of 292 nm (1.4 nm bandpass) with
7.6 msec time resolution. This wavelength was selected to search
for high temperature thermal emission from the impact.

The UV signature of the impact of fragment G is visible in at
least 1 of the traverses of Jupiter across the slit. In a traverse
centered near 1994-199/07:33:32 (corrected to be the time of the
event as seen from Earth), the signal is about 20 percent
brighter than before the impact. There is also a suggestion that
the impact brightening began during the previous traverse, centered
near 07:33:27, and continued into the subsequent traverse centered
near 07:33:37.

These observations were made simultaneously with the boresighted
Galileo NIMS and PPR instruments. Comparison of the data from these
instruments will determine the thermal history and total radiative
output of the G impact.